CN111445835A

CN111445835A - Light emitting display device

Info

Publication number: CN111445835A
Application number: CN201911182415.4A
Authority: CN
Inventors: 曺永成; 苏炳成
Original assignee: LG Display Co Ltd
Current assignee: LG Display Co Ltd
Priority date: 2018-12-28
Filing date: 2019-11-27
Publication date: 2020-07-24
Anticipated expiration: 2039-11-27
Also published as: US11100867B2; EP3675108A1; KR20200081968A; EP3675108B1; CN111445835B; US20200211468A1

Abstract

A light emitting display device is disclosed in which two of three scan signals used by a pixel driving circuit provided in one pixel are supplied through two scan lines provided in the pixel, and the remaining other scan signal is supplied through a scan line provided in another pixel adjacent to the pixel. Therefore, even if the width of one pixel is reduced as the light emitting display device is developed to have high resolution, the pixel driving circuit can accurately sense the threshold voltage of the driving transistor during two horizontal periods using three scan signals.

Description

Light emitting display device

Technical Field

The present disclosure relates to a light emitting display device using an internal compensation scheme.

Background

When the light emitting display panel is used for a long time, a driving transistor supplying a current to the light emitting device may be deteriorated, and the deterioration of the driving transistor causes deterioration of image quality.

In order to compensate for the deterioration of the driving transistor as described above, a pixel driving circuit for controlling the light emitting device includes a plurality of transistors other than the driving transistor.

In particular, in a pixel driving circuit having a plurality of transistors for internal compensation, an operation of sensing a threshold voltage of a driving transistor must be performed.

However, as light emitting display devices are developed to have high resolution, the time allocable for sensing is gradually reduced, eventually reducing the sensing performance of the threshold voltage for internal compensation.

Disclosure of Invention

Accordingly, the present disclosure is directed to a light emitting display device in which one or more problems due to limitations and disadvantages of the related art are substantially overcome.

One aspect of the present disclosure is directed to providing a light emitting display device in which two scan signals of three scan signals used by a pixel driving circuit provided in one pixel are provided through two scan lines provided in the pixel, and the other scan signal is provided through a scan line provided in another pixel adjacent to the pixel.

Additional advantages and features of the disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the disclosure. These objects and other advantages of the present disclosure will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purpose of this disclosure, as embodied and broadly described herein, there is provided a light emitting display device, including: pixels each including a light emitting device outputting light and a pixel driving circuit driving the light emitting device; and a signal line connected to the pixel driving circuit. An nth pixel driving circuit that drives a light emitting device in an nth pixel included among the pixels uses three scan signals, and two of the three scan signals are supplied through two scan lines provided in the nth pixel driving circuit, and the remaining one scan signal is supplied through a scan line provided in an (n +1) th pixel adjacent to the nth pixel, n being an integer equal to or greater than 2.

It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

In the drawings:

fig. 1 is a diagram schematically showing the configuration of a light emitting display device according to the present disclosure.

Fig. 2 is a diagram showing a configuration of a pixel applied to a light emitting display device according to the present disclosure.

Fig. 3 to 8 are diagrams illustrating a method of manufacturing a light emitting display panel applied to a light emitting display device according to the present disclosure.

Fig. 9 is a plan view of an embodiment of an organic light emitting display panel according to the present disclosure.

Fig. 10 is a diagram illustrating a waveform of a signal applied to an organic light emitting display device according to the present disclosure.

Fig. 11 to 15 are diagrams illustrating a method of driving a light emitting display device according to an embodiment of the present disclosure.

Detailed Description

Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Advantages and features of the present disclosure and methods of achieving the same will be clarified by the following embodiments described with reference to the accompanying drawings. This disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. In addition, the present disclosure is limited only by the scope of the claims.

In this application, when reference is made to elements in each figure, it should be noted that wherever possible, like reference numerals, which have been used to designate like elements in other figures, are used for the elements.

The shapes, sizes, proportions, angles and numbers disclosed in the drawings for the purpose of describing embodiments of the present disclosure are by way of example only, and are not intended to be limited to the details shown. Like reference numerals refer to like elements throughout. In the following description, when it is determined that a detailed description of a related known art may unnecessarily obscure the focus of the present disclosure, the detailed description will be omitted. Where the description uses "including," "having," and "containing" in this application, other moieties may be added unless "only" is used. Terms in the singular may include the plural unless indicated to the contrary.

In explaining an element, although not explicitly stated, the element is interpreted to include an error range.

In describing the positional relationship, for example, when the positional relationship between two portions is described as "on … …", "above … …", "below … …", and "after … …", one or more other portions may be provided between the two portions unless "exactly" or "directly" is used.

In describing temporal relationships, for example, when the temporal sequence is described as "after … …", "subsequently", "next", and "before … …", a discontinuous condition may be included unless "exactly" or "directly" is used.

The term "at least one" should be understood to include any and all combinations of one or more of the associated listed items. For example, the meaning of "at least one of a first item, a second item, and a third item" means a combination of all items set forth from two or more of the first item, the second item, and the third item, as well as the first item, the second item, or the third item.

It will be understood that, although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure.

Those skilled in the art can fully appreciate that the features of the various embodiments of the present disclosure can be combined or combined with each other, in part or in whole, and can be technically variously interoperated and driven with each other. Embodiments of the present disclosure may be implemented independently of each other or jointly in an interdependent relationship.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

Fig. 1 is a diagram schematically showing the configuration of a light emitting display device according to the present disclosure. Fig. 2 is a diagram showing a configuration of a pixel applied to a light emitting display device according to the present disclosure. Although a P-type transistor is illustrated in fig. 2, the light emitting display device according to the present disclosure is not limited to the P-type transistor. Fig. 2 also shows the nth pixel driving circuit pdc (n) and the light emitting device ED provided in the nth pixel p (n) among the pixels 110 applied to the present disclosure, n being an integer of 2 or more.

As shown in fig. 1 and 2, a light emitting display device according to the present disclosure includes a pixel 110 and a driver, the pixel 110 including a light emitting device ED outputting light and a pixel driving circuit PDC driving the light emitting device ED, the driver supplying a data voltage Vdata to a signal line connected to the pixel driving circuit PDC and data lines D L1 to D L D connected to the pixel 110 and supplying a scan signal to a scan line G connected to the pixel 110, G shown in fig. 1 denotes a scan line, the signal line includes data lines D L1 to D L D and the scan line G.

The driver may include a data driver 300 supplying a data voltage Vdata to a pixel driving circuit PDC provided in the pixel 110 through data lines D L1 to D L D, a gate driver 200 supplying a scan signal to the scan line G and a light emitting signal em (n) to the light emitting line E L, and a controller 140 controlling driving of the data driver 300 and the gate driver 200, and in addition, the light emitting display device may include a power supply unit supplying required power to the respective components.

In the present disclosure, the nth pixel driving circuit pdc (n) that drives the light emitting device ED disposed in the nth pixel p (n) among the pixels 110 uses three SCAN signals SCAN (n-1), SCAN (n +1), and SCAN (n).

In this case, three SCAN signals SCAN (n-1), SCAN (n +1), SCAN (n-1) among three SCAN signals SCAN (n-1), SCAN (n +1), SCAN (n) and G2 are supplied through two SCAN lines G1 and G2 provided in the nth pixel p (n), and another SCAN signal SCAN (n) is supplied through a SCAN line G3 included in the (n +1) th pixel.

Hereinafter, the above components will be described sequentially.

First, the pixels 110 and the signal lines are disposed in the light emitting display panel 100.

As shown in fig. 1 and 2, the light emitting display panel 100 includes a pixel 110, data lines D L1 to D L D, scan lines G1, G2, and G3, an initialization line I L supplied with an initialization voltage, a light emitting line E L, a first driving voltage line P L a, and a second driving voltage line P L B.

The scan lines G1, G2, and G3 may be formed in a first direction, for example, a width direction of the light emitting display panel 100.

The scan signal is supplied from the gate driver 200 to the pixel driving circuit PDC through the scan lines G1, G2, and G3.

In the nth pixel p (n), the (n-1) th SCAN signal SCAN (n-1) is applied to the first SCAN line G1 among the SCAN lines G1, G2, and G3, the (n +1) th SCAN signal SCAN (n +1) is applied to the second SCAN line G2, and the nth SCAN signal SCAN (n) is applied to the third SCAN line G3.

The data lines D L are formed in parallel with each other at predetermined intervals in a second direction, for example, a length direction of the light emitting display panel 100 to cross the first scan line G1, the second scan line G2, the third scan line G3, the initialization line I L, and the light emitting line E L, a data voltage Vdata is supplied to the data line D L.

The first driving voltage line P L a is formed in the second direction in parallel with the data line D L and spaced apart from the data line D L at regular intervals the first driving voltage line P L a is connected to a power supply unit and supplies the first driving voltage EVDD supplied from the power supply unit to the pixels 110.

The second driving voltage line P L B supplies the second driving voltage EVSS supplied from the power supply unit to the pixels 110.

The light emitting line E L extends in the first direction and supplies a light emitting signal em (n) for controlling the light emitting timing of the light emitting device ED to the pixel 110.

The initialization line I L extends in a first direction and supplies an initialization voltage Vinit to the pixels 110 the initialization voltage Vinit may be supplied from a power supply unit or gate driver 200 to the initialization line I L.

Each pixel 110 includes a light emitting device ED and a pixel driving circuit PDC.

The pixel driving circuit PDC includes a driving transistor Tdr and a storage capacitor Cst for controlling the amount of current supplied to the light emitting device ED. The pixel driving circuit PDC includes first to sixth transistors T1 to T6 and a light emitting device capacitor Coled in addition to the driving transistor Tdr and the storage capacitor Cst.

That is, the pixel driving circuit PDC includes a driving transistor Tdr having a first terminal, a second terminal, and a gate, a first transistor T1 having a gate connected to the second scan line G2, a first terminal connected to the gate of the driving transistor Tdr, and a second terminal connected to the second terminal of the driving transistor Tdr, a second transistor T2 having a gate connected to the third scan line G3584, a first terminal connected to the data line D L, and a second terminal connected to the first terminal of the driving transistor Tdr, a third transistor T3 having a first terminal connected to the first driving voltage line P L a, a second terminal connected to the first terminal of the driving transistor Tdr, and a gate connected to the light emitting line E L, a fourth transistor T4 having a first terminal connected to the second terminal of the driving voltage line P L a, a second terminal connected to the first terminal of the driving transistor Tdr, a gate connected to the light emitting line E L, a fourth transistor T4 having a first terminal connected to the driving voltage line Tdr, a second terminal connected to the driving transistor Tdr, a gate terminal of the light emitting transistor Tdr 865, a light emitting line D, a gate connected to the driving transistor T5926, a light emitting transistor T865, a gate connected to the first terminal of the light emitting transistor T8653, a light emitting transistor T865, a light emitting line tr 2 connected to the gate connected to the light emitting transistor T865, a gate connected to the first terminal connected to the pixel initialization transistor T8653, a storage transistor T865, a light emitting transistor T5926 connected to the gate connected to the first terminal of the pixel initialization transistor T8653 connected to the pixel initialization transistor T869, a storage device, a storage transistor T5926 connected to the pixel initialization transistor T8653 connected to the pixel element, and the storage device, a pixel.

In this case, the first terminal of the light emitting device ED is connected to the second terminal of the fourth transistor T4 and the second terminal of the sixth transistor T6, and the second terminal of the light emitting device ED is connected to the second driving voltage line P L B.

One end of the storage capacitor Cst is connected to a first terminal of the third transistor T3, and the other end of the storage capacitor Cst is connected to a gate of the driving transistor Tdr, i.e., the node N1, a second terminal of the fifth transistor T5, and a first terminal of the first transistor T1.

The storage capacitor Cst may be charged with the data voltage Vdata supplied through the data line D L and the threshold voltage of the driving transistor Tdr.

The driving transistor Tdr is turned on by the data voltage Vdata stored in the storage capacitor Cst and controls the amount of current flowing from the first driving voltage line P L a to the light emitting device ED according to the data voltage Vdata.

The light emitting device ED emits light by the current I supplied from the driving transistor Tdr and emits light having luminance corresponding to the current I.

The third transistor T3 and the fourth transistor T4 are turned on by a light emission signal em (n) transmitted through the light emission line E L to control a light emission timing of the light emitting device ED.

The light emitting device capacitor Coled may be used to constantly maintain a voltage applied to the light emitting device ED.

The fifth transistor T5 supplies the initialization voltage Vinit to the first node N1.

The sixth transistor T6 supplies the initialization voltage Vinit to the light emitting device ED.

The first to sixth transistors T1 to T6 and the storage capacitor Cst perform a function of compensating for a variation in the threshold voltage of the driving transistor Tdr.

A method of performing compensation for a variation in the threshold voltage of the driving transistor Tdr by the first to sixth transistors T1 to T6 and the storage capacitor Cst will be described below with reference to fig. 1 to 15.

Detailed arrangements and forms of the first, second, and third scan lines G1, G2, and G3 will be described in detail below with reference to fig. 1 to 9.

The light emitting device ED includes a first electrode, a light emitting layer disposed on the first electrode, and a second electrode disposed on the light emitting layer. The light emitting layer may include any one of a blue light emitting portion, a green light emitting portion, and a red light emitting portion for emitting light having a color corresponding to the color set in the pixel 110. The light emitting layer may include any one of an organic light emitting layer, an inorganic light emitting layer, or a quantum dot light emitting layer, or may include a stacked structure or a mixed structure of an organic light emitting layer (or an inorganic light emitting layer) and a quantum dot light emitting layer.

Next, the gate driver 200 supplies gate-on signals to the first, second, and third scan lines G1, G2, and G3 using the gate control signal GCS transmitted from the controller 400.

Here, the gate-on signal is a signal capable of turning on transistors connected to the first scanning line G1, the second scanning line G2, and the third scanning line G3. A signal capable of turning off the transistor is referred to as a gate-off signal. The gate-on signal and the gate-off signal are collectively referred to as a scan signal.

The scan signal supplied to the first scan line G1 is referred to as a first scan signal, the scan signal supplied to the second scan line G2 is referred to as a second scan signal, and the scan signal supplied to the third scan line G3 is referred to as a third scan signal.

In addition, the gate driver 200 supplies the light emitting signal em (n) including a gate-on signal capable of turning on the third transistor T3 and the fourth transistor T4 and a gate-off signal capable of turning off the third transistor T3 and the fourth transistor T4 to the light emitting line E L.

The gate driver 200 may be formed separately from the organic light emitting display panel 100 and may be connected to the organic light emitting display panel 100 by a tape carrier package TCP, a chip on film COF, or a Flexible Printed Circuit Board (FPCB). However, the gate driver 200 may be directly formed on the outside of the organic light emitting display panel 100 through a manufacturing process of the pixel driving circuit PDC using a gate-in-panel (GIP) scheme.

Third, the power supply unit supplies power to the gate driver 200, the data driver 300, and the controller 400, and particularly, the power supply unit may supply an initialization voltage Vinit to the initialization line I L.

Fourth, the controller 400 generates a gate control signal GCS for controlling the driving of the gate driver 200 and a data control signal DCS for controlling the driving of the data driver 300 using timing synchronization signals input from an external system. Further, the controller 400 converts input image Data input from an external system into image Data and transfers the image Data to the Data driver 300.

To perform the above functions, the controller 400 may include: a data arrangement unit rearranging input image data transferred from an external system using a timing synchronization signal transferred from the external system and supplying the rearranged image data to the data driver 300; a control signal generation unit generating a gate control signal GCS and a data control signal DCS using the timing synchronization signal; an input unit which distributes the timing synchronization signal and the input image data transmitted from the external system to the data arranging unit and the control signal generating unit; and an output unit outputting the image data generated by the data arrangement unit and the control signals DCS and GCS generated by the control signal generation unit to the data driver 300 or the gate driver 200.

Fifth, the Data driver 300 converts the image Data transferred from the controller 400 into Data voltages, and supplies the Data voltages to the Data lines D L1 to D L D.

Fig. 3 to 8 illustrate a method of manufacturing a light emitting display panel applied to a light emitting display device according to an embodiment of the present disclosure.

First, a multiple buffer layer is formed on a base substrate.

Can be formed by stacking Polyimide (PI), silicon oxide (SiO)₂) And Polyimide (PI) forming the base substrate. In addition, the base substrate may be formed of glass.

The multiple buffer layer may include a buffer layer formed of silicon nitride (SiNx) and a buffer layer formed of silicon oxide (SiO)₂) At least one of the buffer layers formed.

For example, silicon oxide (SiO) may be deposited on top of a buffer layer formed of silicon nitride (SiNx)₂) And forming a buffer layer to form a multiple buffer layer. In addition, silicon oxide (SiO) may be deposited on top of the buffer layer formed of silicon nitride (SiNx)₂) To form multiple buffer layers.

Next, a semiconductor pattern 10 may be formed on top of the multiple buffer layer in such a manner as shown in fig. 3. For example, the semiconductor pattern may be formed of amorphous silicon (a-Si), polycrystalline silicon, and an oxide semiconductor.

Next, the entire surfaces of the semiconductor pattern 10 and the multiple buffer layer are covered with a gate insulating layer. The gate insulating layer may be made of silicon oxide (SiO)₂) And (4) forming.

Next, a first metal pattern is formed on top of the gate insulating layer in such a form as shown in fig. 4. The first metal pattern may be formed of a metal such as molybdenum (Mo), for example.

When viewed from the top to the bottom of fig. 4, a first metal pattern disposed at the top of one pixel 110 among the first metal patterns serves as the first scan line G1, a first metal pattern disposed under the first scan line G1 serves as the second scan line G2, and a first metal pattern disposed under the second scan line G2 serves as the light-emitting line E L.

That is, the first scan line G1, the second scan line G2, and the light emitting line E L are formed through the same process using the same material, and thus, the first scan line G1, the second scan line G2, and the light emitting line E L are disposed in the same layer.

In this case, the first scan line G1, the second scan line G2, and the light emitting line E L extend to all pixels arranged in the first direction of the organic light emitting display panel 100.

Among the first metal patterns, the first metal pattern disposed between the second scan line G2 and the light emitting line E L forms any one terminal ct1 of the storage capacitor Cst the first metal pattern forming any one terminal CT1 of the storage capacitor Cst is independently disposed in each pixel 110, as shown in fig. 4.

Next, the entire surfaces of the first metal pattern and the gate insulating layer are covered with a first insulating layer. The first insulating layer may be formed of silicon nitride (SiNx).

Next, first contact holes CNT0 are formed in the first insulating layer, as shown in fig. 5.

Next, a second metal pattern is formed on the first insulating layer in such a form as shown in fig. 6. The second metal pattern may be formed of a metal such as molybdenum (Mo), for example.

Among the second metal patterns, the second metal pattern extending in the first direction may be used as the initialization line I L. furthermore, the second metal pattern disposed under the initialization line I L forms the other terminal CT2 of the storage capacitor Cst when viewed from the top to the bottom of fig. 6 the second metal pattern forming the other terminal CT2 of the storage capacitor Cst is independently disposed in each pixel 110, as shown in fig. 6.

Next, the entire surfaces of the second metal pattern and the first insulating layer are covered with a second insulating layer. The second insulating layer may be made of silicon nitride (SiNx) or silicon oxide (SiO)₂) And (4) forming.

Next, a second contact hole CNT is formed in the second insulating layer in the form as shown in fig. 7.

Next, a third metal pattern is formed on top of the second insulating layer in such a manner as shown in fig. 8. The third metal pattern may be formed of, for example, at least one of titanium (Ti) and aluminum (Al).

Any one of the third metal patterns serves as the data line D L and the other third metal pattern serves as the first driving voltage line P L a.

Further, among the third metal patterns, the other third metal patterns than the third metal patterns constituting the data line D L and the first driving voltage line P L a may electrically connect the first metal patterns to each other, may electrically connect the second metal patterns to each other, or may electrically connect the first metal patterns and the second metal patterns to each other.

That is, the data line D L and the first driving voltage line P L a are formed through the same process using the same material, and thus the data line D L and the first driving voltage line P L a are disposed in the same layer.

Further, since the data line D L and the first driving voltage line P L a are disposed on top of the second insulating layer covering the initialization line I L, the first driving voltage line P L a and the data line D L are disposed in a different layer from the initialization line I L.

Since the initialization line I L is disposed on top of the first insulating layer covering the first scan line G1, the second scan line G2, and the light emitting line E L, the initialization line I L is disposed in a different layer from the first scan line G1, the second scan line G2, and the light emitting line E L.

Accordingly, the first driving voltage line P L a and the data line D L are disposed in a different layer from the initialization line I L, the first scan line G1, the second scan line G2, and the light emitting line E L.

In this case, the third metal pattern forming the data line D L and the first driving voltage line P L a extends to all the pixels 110 arranged in the second direction.

Among the third metal patterns, other third metal patterns than the third metal patterns forming the data line D L and the first driving voltage line P L a exist in one pixel 110 in an independent form and serve to electrically connect the metal patterns to each other as described above.

In addition, the third metal pattern may perform functions of the first terminal and the second terminal of the transistor.

Finally, the entire surfaces of the third metal pattern and the second insulating layer are covered with a passivation layer, various metal layers, insulating layers, and the like for completing the pixel driving circuit PDC are formed on the top of the passivation layer, and a light emitting device ED may be disposed. Accordingly, the organic light emitting display panel according to the present disclosure may be manufactured.

Here, a process after forming the third metal pattern is the same as or similar to a method of manufacturing a current general organic light emitting display panel, which is not a feature of the present disclosure. Therefore, a detailed description of the process after forming the third metal pattern is omitted.

Fig. 9 is a plan view of an organic light emitting display panel according to an embodiment of the present disclosure. In particular, fig. 9 is a plan view illustrating all components manufactured by fig. 3 to 8. Fig. 9 shows the nth pixel P (n) and the (n +1) th pixel P (n +1) manufactured through the above-described process.

As described in the background of the invention, in the related-art light-emitting display panel, in order to perform an operation of sensing a threshold voltage during two horizontal periods (a period corresponding to twice the period in which a data voltage is supplied to a data line (1 horizontal period)), three scan signals must be supplied to a pixel driving circuit, and in this case, three scan lines must be provided in one pixel.

However, as light emitting display devices are developed to have high resolution, the width of one pixel is reduced, and thus it is increasingly difficult to provide three scanning lines in one pixel.

In order to solve this problem, in the light emitting display device according to the present disclosure, two scan signals of three scan signals used by a pixel driving circuit provided in one pixel 110 are provided through two scan lines provided in the pixel, and the remaining other scan signal is provided through a scan line included in another pixel adjacent to the pixel 110.

For example, when fig. 2 shows the nth pixel driving circuit pdc (n) and the light emitting device ED (n) disposed in the nth pixel P (n) among the pixels 110 applied to the present disclosure and fig. 9 shows the nth pixel P (n) and the (n +1) th pixel P (n +1), the nth pixel driving circuit pdc (n) for driving the light emitting device ED included in the nth pixel P (n) among the pixels 110 uses three SCAN signals, i.e., the first SCAN signal SCAN (n-1), the second SCAN signal SCAN (n +1), and the third SCAN signal SCAN (n).

In this case, two SCAN signals, i.e., the first SCAN signal SCAN (n-1) and the second SCAN signal SCAN (n +1), among the three SCAN signals SCAN (n-1), SCAN (n +1), and SCAN (n) are supplied through two SCAN lines, i.e., the first SCAN line G1 and the second SCAN line G2, provided in the nth pixel driving circuit pdc (n).

The remaining one of the three SCAN signals SCAN (n-1), SCAN (n +1) and SCAN (n) is supplied through the third SCAN line G3 disposed in the (n +1) th pixel P (n +1) adjacent to the nth pixel P (n).

In this case, the nth pixel P (n) and the (n +1) th pixel P (n +1) are adjacent to each other along the data line D L for supplying the data voltage Vdata to the pixels P (n) and P (n + 1).

In other words, the three SCAN signals used in the nth pixel driving circuit pdc (n) are the (n-1) th SCAN signal SCAN (n-1), the nth SCAN signal SCAN (n), and the (n +1) th SCAN signal SCAN (n + 1).

Here, the (n-1) th SCAN signal SCAN (n-1) is supplied through the first SCAN line G1 provided in the nth pixel driving circuit pdc (n) of the nth pixel P (n), the (n +1) th SCAN signal SCAN (n +1) is supplied through the second SCAN line G2 provided in the nth pixel driving circuit pdc (n) of the nth pixel P (n), and the n SCAN signal SCAN (n) is supplied through the third SCAN line G3 provided in the (n +1) th pixel driving circuit of the (n +1) th pixel P (n + 1).

In this case, a light emitting line E L, which is provided in the nth pixel driving circuit pdc (n) of the nth pixel P (n) and supplies a light emitting signal em (n) to the light emitting transistors T3 and T4 that control the light emitting timing of the light emitting device ED, is provided in the boundary portion of the nth pixel P (n) and the (n +1) th pixel P (n + 1).

The second SCAN line G2 supplied with the (n +1) th SCAN signal SCAN (n +1) is spaced further apart from the boundary portion than the light emitting line E L.

The first SCAN line G1 supplied with the (n-1) th SCAN signal SCAN (n-1) is spaced further apart from the boundary portion than the second SCAN line G2.

The driving transistor Tdr is disposed between the second scan line G2 and the light emitting line E L.

At least one of the transistors constituting the nth pixel driving circuit pdc (n) is provided in the (n +1) th pixel P (n + 1).

That is, at least one of the transistors constituting the nth pixel driving circuit pdc (n) is driven by the nth scan signal scan (n) supplied through the third scan line G3 included in the (n +1) th pixel P (n + 1).

For example, the transistors which are driven by the scan line, i.e., the third scan line G3, which constitute the nth pixel driving circuit pdc (n), and which are provided in the (n +1) th pixel P (n +1) are the second transistor T2 and the sixth transistor T6, as shown in fig. 9.

The fifth transistor T5' constituting the (n +1) th pixel driving circuit provided in the (n +1) th pixel P (n +1) may be connected to the third scanning line G3 in addition to the second transistor T2 and the sixth transistor T6 constituting the nth pixel driving circuit pdc (n). That is, two transistors T2 and T6 of the nth pixel P (n) and one transistor T5' of the (n +1) th pixel P (n +1) may be connected to the third scan line G3.

In this case, in the (n +1) th pixel P (n +1), the SCAN line to which the nth SCAN signal SCAN (n) is supplied is the first SCAN line G1 '(i.e., the third SCAN line G3), the SCAN line to which the (n +2) th SCAN signal SCAN (n +2) is supplied is the second SCAN line G2', and the SCAN line to which the (n +1) th SCAN signal SCAN (n +1) is supplied is the third SCAN line. The (n +1) th scan signal to be used in the (n +1) th pixel P (n +1) is supplied in the (n +2) th pixel.

Among the transistors constituting the (n +1) th pixel driving circuit applied to the (n +1) th pixel P (n +1), the third transistor T3 ', the first transistor T1 ', the fourth transistor T4 ', the fifth transistor T5 ', and the driving transistor Tdr ' are disposed in the (n +1) th pixel P (n +1), and the second transistor and the sixth transistor are disposed in the (n +2) th pixel.

Hereinafter, a method of driving a light emitting display device according to the present disclosure will be described with reference to fig. 1 to 15. In the following description, the same or similar contents as those described with reference to fig. 1 to 9 are omitted or briefly described.

Fig. 10 is a diagram illustrating a waveform of a signal applied to an organic light emitting display device according to the present disclosure. Fig. 11 to 15 are diagrams illustrating a method of driving a light emitting display device according to the present disclosure.

First, as shown in fig. 10, during the first period a, the first SCAN signal SCAN (n-1) having a low level is supplied to the fifth transistor T5, the second SCAN signal SCAN (n +1) having a high level is supplied to the first transistor T1, the third SCAN signal SCAN (n) having a low level is supplied to the second transistor T2 and the sixth transistor T6, and the emission signal em (n) having a high level is supplied to the third transistor T3 and the fourth transistor T4.

Accordingly, as shown in fig. 11, the fifth transistor T5, the second transistor T2, and the sixth transistor T6 are turned on, and the first transistor T1, the third transistor T3, and the fourth transistor T4 are all turned off.

In this case, the first node N1 connected to the gate of the driving transistor Tdr is initialized by the initialization voltage. That is, the voltage of the first node N1 is an initialization voltage.

Since the initialization voltage Vinit is also transmitted to the light emitting device ED through the sixth transistor T6, the light emitting device ED is also initialized to the initialization voltage Vinit.

Next, as shown in fig. 10, during the second period B, the first SCAN signal SCAN (n-1) having a high level is supplied to the fifth transistor T5, the second SCAN signal SCAN (n +1) having a low level is supplied to the first transistor T1, the third SCAN signal SCAN (n) having a low level is supplied to the second transistor T2 and the sixth transistor T6, and the emission signal em (n) having a high level is supplied to the third transistor T3 and the fourth transistor T4.

Accordingly, as shown in fig. 12, the first transistor T1, the second transistor T2, the driving transistor Tdr, and the sixth transistor T6 are turned on, and the third to fifth transistors T3 to T5 are all turned off.

In this case, the data voltage Vdata is supplied to the first node N1 through the data line D L, the second transistor T2, the driving transistor Tdr, and the first transistor T1.

Accordingly, the data voltage Vdata and the threshold voltage of the driving transistor Tdr are supplied to the first node N1. Accordingly, the data voltage Vdata and the threshold voltage are charged in the storage capacitor Cst.

Further, the light emitting device ED is continuously initialized to the initialization voltage Vinit.

Next, as shown in fig. 10, during the third period C, the first SCAN signal SCAN (n-1) having a high level is supplied to the fifth transistor T5, the second SCAN signal SCAN (n +1) having a low level is supplied to the first transistor T1, the third SCAN signal SCAN (n) having a high level is supplied to the second transistor T2 and the sixth transistor T6, and the emission signal em (n) having a high level is supplied to the third transistor T3 and the fourth transistor T4.

Thus, as shown in fig. 13, the first transistor T1 is turned on, and the second to sixth transistors T2 to T6 are all turned off.

In this case, the data voltage Vdata supplied to the first terminal of the driving transistor Tdr during the second period B, i.e., to the second node N2 shown in fig. 13, is no longer supplied to the second node N2 because the second transistor T2 is turned off during the third period C. In this case, the driving transistor Tdr may be turned on by the data voltage supplied to the first node N1 during the second period B, and thus the data voltage Vdata supplied to the second node N2 in a floating state may be supplied to the first node N1 through the driving transistor Tdr. In this case, the threshold voltage of the driving transistor Tdr may also be applied to the first node N1.

Accordingly, the threshold voltage of the driving transistor Tdr may be continuously charged in the storage capacitor Cst connected to the first node N1.

That is, in the present disclosure, the threshold voltage of the driving transistor Tdr may be charged in the storage capacitor Cst during the second and third periods B and C, i.e., during the two horizontal periods. Accordingly, the threshold voltage of the driving transistor Tdr can be effectively stored in the storage capacitor Cst, and thus the compensation efficiency of the threshold voltage can be increased.

Next, as shown in fig. 10, during the fourth and fifth periods D and E, the first SCAN signal SCAN (n-1) having a high level is supplied to the fifth transistor T5, the second SCAN signal SCAN (n +1) having a high level is supplied to the first transistor T1, the third SCAN signal SCAN (n) having a high level is supplied to the second and sixth transistors T2 and T6, and the light emission signal em (n) having a high level is supplied to the third and fourth transistors T3 and T4.

Thus, as shown in fig. 14, the first to sixth transistors T1 to T6 are all turned off.

In this case, the voltage of the first node N1 is maintained as the sum of the threshold voltage Vth of the driving transistor Tdr and the data voltage Vdata. That is, the storage capacitor Cst is charged with the threshold voltage and the data voltage.

Finally, as shown in fig. 10, during the sixth period F, the first SCAN signal SCAN (n-1) having a high level is supplied to the fifth transistor T5, the second SCAN signal SCAN (n +1) having a high level is supplied to the first transistor T1, the third SCAN signal SCAN (n) having a high level is supplied to the second transistor T2 and the sixth transistor T6, and the emission signal em (n) having a low level is supplied to the third transistor T3 and the fourth transistor T4.

Accordingly, as shown in fig. 15, the first transistor T1, the second transistor T2, the fifth transistor T5, and the sixth transistor T6 are turned off, and the third transistor T3, the driving transistor Tdr, and the fourth transistor T4 are all turned on.

Since the data voltage Vdata and the threshold voltage Vth are supplied to the gate of the driving transistor Tdr, the driving transistor Tdr is also turned on.

Accordingly, a current may be supplied to the light emitting device ED, which may output light having a luminance corresponding to the current, through the third transistor T3, the driving transistor Tdr, and the fourth transistor T4.

In this case, the voltage applied to the gate of the driving transistor Tdr is [ Vdata + Vth ], the voltage applied to the source of the driving transistor Tdr is the first driving voltage EVDD, and the current passing through the driving transistor Tdr is proportional to a voltage obtained by subtracting the threshold voltage Vth of the driving transistor Tdr from the difference voltage (Vgs ═ Vdata + Vth-EVDD) between the gate and the source of the driving transistor Tdr.

That is, the current I supplied to the light emitting device ED through the driving transistor Tdr may be represented by formula 1 below.

[I∝(Vgs-Vth)²=(Vdata+Vth-EVDD-Vth))²=(Vdata-EVDD)²]---[1]

The current supplied to the light emitting device ED through the driving transistor Tdr is determined by the data voltage Vdata and the first driving voltage EVDD, not by the threshold voltage Vth of the driving transistor Tdr.

In general, as the organic light emitting display device is used for a long time, the driving transistor Tdr may be deteriorated, and thus the threshold voltage Vth of the driving transistor Tdr may be varied.

In addition, the degree of deterioration of the driving transistor Tdr included in the pixel 110 formed in the organic light emitting display panel 100 may be different according to various reasons.

When the deterioration degrees of the driving transistors Tdr are different, the threshold voltages Vth of the driving transistors Tdr are also different from each other.

When the threshold voltages Vth of the driving transistors Tdr are different from each other, even if the same data voltage Vdata is supplied to the driving transistors Tdr, the magnitude of the current supplied to the light emitting device ED through the driving transistors Tdr may be different. As a result, the light emitting devices ED included in the pixels supplied with the same data voltage Vdata may output light of different brightness.

In order to solve the above problem, the present disclosure is configured such that the current flowing through the driving transistor Tdr is not affected by the threshold voltage Vth of the driving transistor Tdr.

That is, in the present disclosure, by the structure of the pixel as shown in fig. 2 and the driving method described with reference to fig. 10 to 15, the magnitude of the current I passing through the driving transistor Tdr is not affected by the threshold voltage of the driving transistor Tdr, as shown in equation 1.

Therefore, according to the present disclosure, even if the driving transistor Tdr deteriorates, a normal current corresponding to the data voltage Vdata may be supplied to the light emitting device ED in each pixel, and thus the light emitting device ED may output light having a luminance proportional to the data voltage Vdata.

In particular, in the present disclosure, two scanning lines of the three scanning lines required for the above-described operation are arranged in one pixel, and the other scanning line is provided in another pixel adjacent to the pixel.

Thus, according to the present disclosure, even if the width of the pixel is reduced as the light emitting display device is developed to have high resolution, the pixel driving circuit can accurately detect the threshold voltage of the driving transistor during two horizontal periods using three scan signals. Further, in the above description, the storage capacitor Cst is charged to the threshold voltage of the driving transistor Tdr during two horizontal periods, i.e., the second period B and the third period C, but if the width of the scan signal is increased to three horizontal periods, the storage capacitor may be charged to the threshold voltage of the driving transistor Tdr during three horizontal periods.

For example, in fig. 10, if the (n-1) th SCAN signal SCAN (n-1) is increased by 1 horizontal period in the forward direction of the first period a, the n-th SCAN signal SCAN (n) is also increased by 1 horizontal period in the forward direction of the first period a, and the (n +2) th SCAN signal having a width of 1 horizontal period in the forward direction of the fourth period D replaces the (n +1) th SCAN signal SCAN (n +1) shown in fig. 10, the storage capacitor may be charged to the threshold voltage of the driving transistor Tdr during a total of three horizontal periods from the second period B to the fourth period D.

That is, in the present disclosure, the period in which the threshold voltage of the driving transistor Tdr is charged is not limited to two horizontal periods, but may be increased to three horizontal periods or longer according to the pulse width of the scan signal and the order of the scan signal.

According to the present disclosure, the threshold voltage of the driving transistor may be sensed during two horizontal periods using three scan signals. Therefore, the threshold voltage can be sensed more accurately than the related art light emitting display device.

Further, according to the present disclosure, in order to sense the threshold voltage of the driving transistor during the two horizontal periods, two scan signals of the three scan signals used by the pixel driving circuit provided in one pixel may be provided through two scan lines provided in the pixel, and the remaining another scan signal may be provided through a scan line provided in another pixel adjacent to the pixel. Therefore, even if the width of one pixel is reduced as the light emitting display device is developed to have high resolution, the pixel driving circuit can accurately sense the threshold voltage of the driving transistor during two horizontal periods using three scan signals.

The above-described features, structures, and effects of the present disclosure are included in at least one embodiment of the present disclosure, but are not limited to only one embodiment. Further, the features, structures, and effects described in at least one embodiment of the present disclosure may be achieved by a person skilled in the art through combination or modification of other embodiments. Therefore, matters related to combination and modification should be construed as being within the scope of the present disclosure.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the spirit or scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

Claims

1. A light emitting display device comprising:

pixels each including a light emitting device outputting light and a pixel driving circuit driving the light emitting device; and

a signal line connected to the pixel driving circuit,

wherein an nth pixel drive circuit that drives a light emitting device in an nth pixel included among the pixels uses three scan signals, and

two of the three scanning signals are supplied through two scanning lines provided in the nth pixel driving circuit, and the remaining one scanning signal is supplied through a scanning line provided in an (n +1) th pixel adjacent to the nth pixel, n being an integer of 2 or more.

2. The light emitting display device of claim 1, wherein

At least one of transistors constituting the nth pixel driving circuit is provided in the (n +1) th pixel and is driven by the scanning line provided in the (n +1) th pixel.

3. The light emitting display device of claim 1, wherein

The nth pixel and the (n +1) th pixel are adjacent along a data line supplying a data voltage to the pixels.

4. The light emitting display device of claim 1, wherein

The three scanning signals used in the nth pixel driving circuit are an (n-1) th scanning signal, an nth scanning signal, and an (n +1) th scanning signal.

5. A light emitting display device according to claim 4, wherein

The (n-1) th scan signal is supplied through a first scan line provided in the nth pixel driving circuit, the (n +1) th scan signal is supplied through a second scan line provided in the nth pixel driving circuit, and the nth scan signal is supplied through a third scan line provided in the (n +1) th pixel.

6. A light emitting display device according to claim 5, wherein

A light emitting line provided in the nth pixel driving circuit and supplying a light emitting signal to a light emitting transistor controlling a light emitting timing of the light emitting device is provided in a boundary portion of the nth pixel and the (n +1) th pixel among the pixels, the second scan line supplied with the (n +1) th scan signal is further separated from the boundary portion than the light emitting line, the first scan line supplied with the (n-1) th scan signal is further separated from the boundary portion than the second scan line, and a driving transistor is provided between the second scan line and the light emitting line.

7. A light emitting display device according to claim 6, wherein

At least one of the transistors constituting the nth pixel driving circuit is provided in the (n +1) th pixel.

8. A light emitting display device according to claim 5, wherein

At least one of the transistors constituting the nth pixel driving circuit is driven by the nth scan signal supplied through the third scan line provided in the (n +1) th pixel.

9. The light emitting display device of claim 1, wherein

The pixel driving circuit includes:

a drive transistor having a first terminal, a second terminal, and a gate;

a first transistor having a gate connected to a second scan line, a first terminal connected to the gate of the driving transistor, and a second terminal connected to the second terminal of the driving transistor;

a second transistor having a gate connected to a third scan line, a first terminal connected to a data line, and a second terminal connected to the first terminal of the driving transistor;

a third transistor having a first terminal connected to a first driving voltage line, a second terminal connected to the first terminal of the driving transistor, and a gate connected to a light emitting line;

a fourth transistor having a first terminal connected to the second terminal of the driving transistor, a second terminal connected to the light emitting device, and a gate connected to the light emitting line;

a fifth transistor having a gate connected to the first scan line, a first terminal connected to the initialization line, and a second terminal connected to the gate of the driving transistor;

a sixth transistor having a gate connected to the third scan line, a first terminal connected to the initialization line, and a second terminal connected to the second terminal of the fourth transistor and the light emitting device; and

a storage capacitor connected to the first terminal of the third transistor and the gate of the drive transistor.

10. A light emitting display device according to claim 9, wherein

The second transistor and the sixth transistor constituting the nth pixel drive circuit are provided in the (n +1) th pixel.

11. The light emitting display device of claim 1, wherein

During a first period, a first node connected to a gate of a driving transistor for controlling a magnitude of a current flowing to the light emitting device is initialized by an initialization voltage,

during a second period, a storage capacitor connected to the first node is charged to a data voltage and a threshold voltage of the driving transistor,

during a third period, the storage capacitor is charged to the data voltage and the threshold voltage of the driving transistor,

during the fourth period and the fifth period, the voltage of the storage capacitor is maintained as the sum of the data voltage and the threshold voltage, and

during a sixth period, a current corresponding to the data voltage is supplied to the light emitting device through the driving transistor.